1. Field of the Invention
The present invention relates to a heat exchanger which is used in an air conditioner or the like.
2. Description of Related Art
The heat exchanger is normally provided with plate-like members for exchanging heat (or plate-like heat exchange members) which perform heat exchanging with a fluid such as air or the like which flows along surfaces thereof.
Attempts have so far been made to improve an efficiency of heat exchanging (or a heat exchange efficiency) by devising the shape of the heat exchange members. For example, as shown in FIG. 14, there is known a heat exchanger in which louver-like fin portions b are formed in the heat exchange members "a" so that the heat exchange efficiency can be improved by a leading-edge effect (i.e., an effect to be attained by the leading edge) of each of the fins b.
Even if the fins are formed as described above, there will be generated a speed boundary layer of lower speed on the surfaces of the fins due to the friction of the fluid with the fins when the fluid flows from the leading edge of each of the fins towards the trailing edge thereof. As a result, the fluid on the surfaces of the fins becomes hardly replaced or interchanged. Further, there will occur a deficit in flow speed (or a flow speed deficit) in the neighborhood of the surfaces of the fins, resulting in a pressure loss. Especially, that portion of a boundary layer which is very close to the surfaces of the fins and which is subjected to the influence of the adsorbing phenomenon of the fluid molecules will not be eliminated or will not disappear even if the shape of the fins were changed. This fact has been a hindrance to an attempt to improve the heat exchange efficiency.
In view of the above-described points, the present invention has an object of providing a heat exchanger which can improve the heat exchange efficiency by eliminating the speed boundary layer.